Apparatus for twisting cord



July 19, 1955 R. B. ESLER 2,713,242

' APPARATUS FOR TWISTING CORD Filed Sept. 20, 1954 IN VEN T OR.

Eff/551F175 -55L if BY QMZWM United States Patent 0 APPARATUS FOR TWISTING CORD Richard B. Esler, Clinton, Ohio, assignor to The Firestone Tire & Rubber Company, Akron, Ohio, a corporation of Ohio .tpplication September 20, 1954, Serial No. 457,271

2 Claims. (CI. 57-12) It is often highly desirable to produce twisted yarn f products having an axial core portion of one type of yarn surrounded by a covering of another type of yarn twisted around the core portion in a helical configuration. A particularly desirable construction of this type comprises a camel core of a highly elastic yarn of great tensile strength, such as nylon or glycol terephthalate polyester yarns, surrounded by a less elastic yarn such as tenacity viscose rayon yarn. Such a construction ties the elasticity and strength of the nylon yarn with the better dimensional stability of the rayon yarn. The rayon yarn does not interfere with the initial elastic elongation of the nylon yarn, since it is helically disposed around the nylon yarn and can elongate slightly by straightening or" its helical convolutions; however, this elongation is limited by the degree to which the rayon yarn may be uncoiled, so that the dimensional stability of the yarn as a whole is excellent. The manufacture of such desirable composite twisted yarns, however, presents considerable difiiculty.

It has been discovered by the present patentee that if a yarn intended for a core yarn is fed together with a plurality of covering yarns to a twisting machine (such as a ring, cap or flyer twisting machine) and if the core yarn is supplied to the machine at a slower rate than the covering yarn, the core yarn will automatically gravitate to the axis of the spun twisted product and the cover yarn will automatically dispose itself peripherally around the core yarn in a helical configuration. One apparatus which the present inventor has devised for this purpose involves two sets of feed rolls, one for the A further object is to provide a more compact and simply constructed apparatus of this type.

A further object is to provide a device of this type which may be arranged to supply the core and cover yarns in speed ratios which are independent of the incremental speed ratios obtainable by gearing.

A still further object is to provide such an apparatus in which the speed ratios of core and cover yarn may be quickly, simply and exactly adjusted.

The invention will be described in connection with the accompanying drawings wherein:

Fig. l is an enlarged perspective View of a twisted yarn product such as is produced by the apparatus of this invention;

Fig. 2 is a front view of a set of yarn-supporting rollers for use in this invention;

Fig. 3 is a section along the line 33 of'Fig. 2;

Fig. 4 is a general assembly view of the apparatus of this invention, and

Fig. 5 shows a general assembly View in perspective of a modification of this invention involving special yarn guides.

Referring now to the drawings, and more particularly to Fig. 1, there is shown a twisted yarn product such as it is the object of this invention to produce, comprising a central axial core ll of nylon yarn surrounded by a plurality of high tenacity viscose rayon yarns 12. twisted helically therearound. Such a yarn is characterized, at low stresses, by the excellent elasticity of the nylon core 16, which elasticity is not hampered by the rayon yarns 12, since the latter accommodate themselves to low values of elongation by slight uncoiling of their helical convolutions about the core 10. However, beyond low elongations, the dimensional stability of the rayon asserts itself, so that the construction as a whole is characterized by good dimensional stability. Furthermore, the construction has the benefit of the high tensile strength of the nylon yarn. These properties render the twisted yarn products of Fig. 1 highly desirable for many applications, notably as reinforcing cords for rubber articles such as tires, conveyor and power belts, fuel cells and the like.

Referring now to Fig. 4, there is shown a complete apparatus in accordance with this invention, comprising a set of supply bobbins 16 supplying rayon yarns 12, and

a supply bobbin 14 supplying the nylon core yarn 10.

core yarn and one for the cover yarn, together with a gear train between said sets of feed rolls, whereby the feed rolls for the cover yarn are driven at a somewhat higher speed than the feed rolls for the core yarn. This apparatus was fairly satisfactory, but involved a complicated gear train and was somewhat inflexible since the gear ratios could be changed only incrementally, rather than continuously which made it impossible in some cases to make an exact optimum adjustment of speed ratio of the two sets of feed rolls.

Accordingly, it is an object of this invention to pro vide a novel and improved apparatus for the twisting together of core and cover yarns to produce twisted structures in which the core yarn is disposed at the axis of the twisted product and the cover yarn is twisted helically therearound.

Another object is to provide such an apparatus making use of the principle of differential supply of the core and cover yarns described hereinabove.

Another object is to avoid the use of change speed gearing in such a twisting device.

22 will :4, in greater detail.

3 nously in a counter-clockwise direction as viewed A differential feed roller apparatus 18 withdraws the nylon yarn and rayon yarns from the reels 14 and 16 and supplies them to a pigtail eyelet 29 disposed axially of, and above, a ring twister 22. As will appear more fully hereinafter, the feed roller device 18 withdraws the rayon yarn 12 and supplies it to the eyelet 29 and spinning apparatus 22 at a slightly greater linear speed than the nylon yarn 1i). it has been discovered by the applicant that, under these conditions of yarn supply, the twisting device produce a twisted product such as that shown in Fig. 1, in which the nylon yarn 1%) is disposed as a central core surrounded by the ra on yarns 12 positioned thereabout in helical convolutions as a covering.

Figs. 2 and 3 show the differential speed roll device 18 The device comprises a pair of juxtaposed cylindrical drive rclls 2 and 26 mounted in suitable bearings (not shown) with their axes parallel to each other and disposed in a horizontal plane. These two rolls are of equal diameter and are both driven synchroin Fig. 3 by means of gearing (not shown). One section of each of the rolls 24 and 26 is surrounded by a close-fitting cylindrical sleeve 32 and 34 respectively, the outer surface of each of these sleeves 32 and 34 being concentrio with its inner surface so that the outer surface provides an enlarged cylindrical surface concentric with its respective roll 24 or 26. Each of the sleeves 32 and 34 3 is secured to its drive roll by means of a set screw 38 so as to rotate with its respective roll. The outside diameters of the two sleeves 32 and 34 are equal, so that the peripheral speeds thereof as they revolve with their respective rolls are equal and, due to their slightly greater diameters with respect to the rolls 24 and 26, their said peripheral speeds are slightly greater than the peripheral speeds of the bare portions of the rolls 24 and 26. The sleeves 32- and 34 are secured to their shafts at corresponding longitudinal positions thereon so that they are opposite each' other; i. e., in geometrical terms, the ends of the cylindrical surfaces of the sleeves 32 and 34 lie in common planes perpendicular to the axes of the rolls 24 and 26.

An idler roll 28 rides in the valley between the bare portions of the rolls 24 and 26 and a second idler roll 40 rides in the valley between the cylindrical sleeves 32 and 34, both of these rolls being held in place in their respective valleys and against the rolls 24 and 26 and sleeves 32 and 34 by gravity. The frictional engagement of the idler rolls 28 and 48 respectively with the rolls 24 and 26 and with sleeves 32 and 34 causes them to be driven'in a rotary clockwise direction. A pair of fixed brackets 41 and 43 bear against bosses 45 and 47 on the ends of the idler rolls 28 and 40 to confine them against longitudinal movement.

The diameters of the rolls 28 and 40 are so chosen that thesum of the diameters of the roll 24 (or 26) and roll 28 is equal to the sum of the diameters of the roll 40 and sleeve 32 (or 34). coaxial with the roll 28, so that the motions of their adjacent ends with respect to each other is that of simple rotation, rather of planetation, as would'otherwise be As a result, the roll 40 is the case. A stub shaft 49 projects from the end of the idler roll 287adjacent to the idler roll 40 and fits into a shallow socket in the. end of the roll 40, both the stub shaft and thersocket being coaxial with the rolls 28 and 40.

I Thisstub shaft 49 serves to keep the rolls 28 and 40 spaced slightly apart, while permitting their relative rotations with respect to each other.

In operation, the nylon core yarn is passed from the bobbin 14, down through a pigtail eyelet secured to the frame of the machine, and thence under the driven roll 24, over the idler roll 28 and under the driven feed;

roll- 26 to the pigtail eyelet 2% 'Similarly, the rayon cover yarns 12 are fed through a pigtail eyelet 41'secured to the frame of the machine and passed thence under the cylindrical sleeve 32, over the idler roll 40, under the cylindrical sleeve 34 and to the pigtail eyeletltl where they are united with the nylon core yarn. The frictional engagement of the rolls 24 and 26 with the core yarn 16,

and of .the sleeves 32 and 34 with the cover yarns 12, withdraw these yarns from their bobbins 14 and 16 and feeds them to the eyelet 20. Since the peripheral speed of the sleeves 32 and 34 and idler roll engaging the M cover yarn '12 is greater than the peripheral speed of the corresponding, rolls 24, 26 and 28 engaging the core yarn 10, the cover yarns are fed at a slightly greater linear I speed than the core yarn 10. As pointed out hereinabove,

this results in the core yarn being disposed as a core in the center of the final twisted'product produced by the spinning device 22.

More particular with regard to this differential speed in the feeding of the core and cover yarns, it will be seen that the present invention makes possible a precise adjustment of this ratio, and a quick change of this ratio, if

this is desired. Thus the diameters of the sleeves 32.

34, being secured to the rolls 24 and 26 only by sliding fit and by the set screw 38, may be quickly removed and replaced with other sleeves having other different diameters wherever it is desired to shift from the manufacture of a product requiring one ratio of feeding of core and cover yarns to another product requiring a different ratio of these factors. It will be understood of course that this invention is not confined to an apparatus in which the enlargement of the cover-yarn-supplying section of the rolls 24 and 26 is provided by the sleeves 32 and 34 which are removable from the rolls 24 and 26; for instance, the sleeves 32 and 34 may be replaced by corresponding integral enlargements of the rolls 24 and 26 having the same overall contour. However, this would sacrifice one of the more specific advantages of this invention, namely the removability feature of the sleeves 32 and 34, which permits of a quick change in the ratios of supply of the core and cover yarns.

Fig. 5 shows a modification of the present invention 1 in which there is used a special die assembly 50 rather than the simple pigtail eyelet'20. As discussed above, it has been found that simple differential feeding of core and cover yarns to a simple eyelet 20 and thence to a spinning device will cause the desired coreyarn to seek the center of the twisted product. In some cases of yarns which are of a somewhat refractory nature, having excessive spring or previous twist, occasional variations may occur if the apparatus is carelessly operated. To minimiZe such dilhculties it may, in some cases, be desirable to provide a special guide which positively assembles'the yarns with the core yarn in the center, so as to supplement the action of diiferential rate of feeding the yarns. Such a device is shown in Fig. 5 as comprising an upper eyelet plate 52 nearest to differential feeding device 18 and a lower eyelet plate 54 between the upper eyelet plate 52 and the ring spinner 22. The upper eyelet plate has a central eyelet 58 through which the core yarn 10 is threaded. Surrounding the central eyelet 58, and disposed upon a circle concentric with the eyelet 58,,are a plurality of eyelets 60 are passed. All the yarns passing through the eyelets 5 8 and 6b are assembled and pass through a single eyelet 62 in thelower eyelet plate 54. It will be seen that the above construction insures that'the core yarn 10 isfed centrally of all the other yarns, thus providing additional assurance that thecore yarn 10 will occupy its proper central axial position in the final twisted product.

It will be understood that the invention 7 described above is subject to many variations. For instance, the

ring spinner 22 may be replaced by various other conven-' tional spinning devices, such as cap spinners, flyer spinners and the like. Likewise the invention has been illustrated in an embodiment in which a single yarn 10 is used as the core. The yarn 10 may. be'replaced with two,

three or even more yarns to provide a multi-yarn central 7 core with the cover yarns twisted therearound.

From the foregoing general disclosure and detailed description it will be evident that this invention provides a novel spinning device for the manufacture of twisted textile products having a central core yarn surrounded by cover yarn. The apparatus is simple and inexpensive, and readily adapted to existing textile machinery. Eurthermore, it is capable of a much more exact adjustment in operation than other conceivable mechanisms produc- 'ing the same result. The apparatus is quickly adaptable to the manufacture of products requiring different ratios of supply for the core and cover yarns.

What is claimed is: V

1. Apparatus for twisting together core yarn and cover yarn to form a twisted textile structure :in which the core yarn forms a core in the interior of the twisted product with the cover yarn twisted therea'round in a helical disposition, comprising a pair of rotating cylindrical drive rolls arranged in proximity to each other with their axes horizontal and parallel, both of said drive rolls being positively and synchronously driven, each through which the cover yarns 12' of said drive rolls being divided longitudinally into a first section and a second section, which latter section has a cylindrical sleeve secured coaxialiy therearound to provide a cylindrical enlargement thereon so that the peripheral speed of the exterior surface of the sleeve is greater than that of the bare surfaces of the drive rolls, a first and a second cylindrical idler roll disposed with their axes parallel to said drive rolls and riding in the valley between said drive rolls and bearing thereagainst at said first section and said sleeves respectively, a source for supplying core yarn to the intake of the nip between the first idler roll and the first drive roll so as to be withdrawn from said source, a second source for supplying cover yarn to the nip between the second idler roll and the sleeve on said first drive roll so as to be withdrawn from said second source, said core and cover yarns being supplied from below the valley between said drive rolls into said nips and passing thence over the idler rolls respectively into the nip between the first idler roll and the second drive roll and into the nip between said second idler roll and the sleeve on said second drive roll, the greater peripheral speed of said sleeves resulting in a greater linear speed of withdrawal of said cover yarn than of said core yarn from said sources, a yarn twisting device, and means for guiding said core and cover yarns, as they emerge from the nips of said second drive roll and its sleeve and the idler rolls, together and to said twisting device, said guiding means including a stationary plate having a central eyelet for said core yarn and a plurality of eyelets disposed at even intervals on a circle concentric with said eyelet, said eyelets on said circle accommodating said cover yarn, the greater speed at which the cover yarn is withdrawn causing it to be displaced to the exterior of the twisted product produced by said twisting device.

2. Apparatus for twisting together core yarn and cover yarn to form a twisted textile structure in which the core yarn forms a core in the interior of the twisted product with the cover yarn twisted therearound in a helical disposition, comprising a pair of rotating cylindrical drive rolls arranged in proximity to each other with their axes horizontal and parallel, both of said drive rolls being positively and synchronously driven, each of said drive rolls being divided longitudinally into a first section and a second section, which latter section has a cylindrical sleeve secured coaxially therearound to provide a cylindrical enlargement thereon so that the peripheral speed of the exterior surface of the sleeve is greater than that of the bare surfaces of the drive rolls, a first and a second cylindrical idler roll disposed with their axes parallel to said drive rolls and riding in the valley between said drive rolls and bearing thereagainst at said first section and said sleeves respectively, the diameter of the first and second rolls being equal, the external diameter of the sleeves thereon being equal, and the sum of the diameter of either drive roll plus the diameter of the first idler roll being equal to the sum of the diameter of either of the sleeves plus the diameter of second idler roll, so that the first and second idler rolls will be disposed coaxially of each other as they ride in said valley, a stub shaft extending coaxially of one of said idler rolls and fitting into a bearing in the other of said idler rolls, a source for supplying core yarn to the intake of the nip between the first idler roll and the first drive roll so as to be withdrawn from said source, a second source for supplying cover yarn to the nip between the second idler roll the sleeve on said first drive roll so as to be withdrawn from said second source, said core and cover yarns being supplied from below the valley between said drive rolls into said nips and passing thence over the idler rolls respectively into the nip between the first idler roll and the second drive roll and into the nip between said second idler roll and the sleeve on said second drive roll, the greater peripheral speed of said sleeves resulting in a greater linear speed of withdrawal of said cover yarn than of said core yarn from said sources, a yarn twisting device, and means for guiding said core and cover yarns, as they emerge from the nips of said second drive roll and its sleeve and the idler rolls, together and to said twisting device.

References Cited in the file of this patent UNITED STATES PATENTS 784,922 Collins Mar. 14, 1905 1,728,066 Lay Sept. 10, 1929 2,332,395 Nutter et al Oct. 19, 1943 FOREIGN PATENTS 308,470 Great Britain Mar. 28, 1929 370,908 France Jan. 5, 1907 

